Cropped Images Print Darker Than Originals

I hope I am in the right place - wasn't sure if this came under software or printing, but here goes.

I had 25 or so Jpeg images I wanted to have printed. The images were taken on a Nikon D70 in Jpeg format, not Raw.

Some of these I cropped using Nero Photosnap Essentials - the only thing I did was crop the images; I did no other manipulation. I saved the cropped images with the same name as the originals but with the word CROP on the end.

I then uploaded both the original images and the cropped ones to UK online photo print service Photobox. I've used them many times in the past, and had cropped images printed with no problem. The results are always good and the service is unbelievably quick.

When I got the printed pictures through the post, all of the cropped versions were much darker than the originals. I am not a photography expert ( in fact the Nikon D70 wasn't mine ), and couldn't understand why this would be so. They are not just slightly darker, but much more so.

I looked back at both sets of jpegs on my PC, and also on the online album which I had uploaded them to. They look OK there. I also printed out a couple to see if this happened using my own printer, and it doesn't.

So I emailed Photobox about this, and they replied thus:"Hi

Thanks for your email. The darkness of cropped images is due to something called 'EXIF'. This is information held in a JPEG file that indicates things such as the camera that was used to take the photo, the date and time, and the settings used on the camera. If the image has been edited (cropped for example) then the editing software is also included.

When the printers identify that an image has been edited, they print the images 'as is' i.e. they make no adjustments to the image at all prior to printing, However, if no changes have been made, they will sometimes.

Kind regards(name deleted)"

Can anyone make any sense of this ? I can't help thinking there's someting missing from the answer. But is it correct that cropping the image will affect the Exif information in such a way as to render the image darker when printing it out using a professional print service ?

I just want to have the proper iknowledge to hand before I reply to them, as it just doesn't sound right to me - but I may be wrong of course. Also, would my choice of editing software (Nero Photosnap) make a difference. I don't normally do much to photos before I get them printed, and the only reason I used the Nero sotware was that it just happened to be on the new laptop PC I have.

I'm certainly no expert on the subject but I always thought Exif was just a metadata tag that had no bearing on image quality. I'm surprised at the answer you got from your processing company. I read about Exif in Wikipedia and checked the forum web page at Exif.org and could find nothing that would support the answer you received.

In the world of digital photography, cutting executive software. When the photo is a bit of data, there is no need to separate the size of the crop - the software and printing process can stretch the image to fit.

A digital image has something called a 'colour space' attached. This tells the equipment that 'uses' the photo (screen and printers) how the colours should be displayed.

It is possible that your Nero photo editing software has attached a different colour space to your images automatically on saving...

But I actually think that what the answer you received from Photobox is trying to say is that if you send images that have not been edited then they will automatically make some corrections for you (they will definitely lighten them because printed images are always darker). But if you send them edited (i.e. cropped in your case) then they will not make any changes because the image has been edited already and they will assume that the editor has made all the decisions regarding how they want the final image to look (including brightness). So your edited images have been printed as they are and your unedited ones have automatically been lightened...